1. Field of the Invention
The present invention relates to an apparatus for picking up plant material lying on the ground, having at least one rotor revolving around a vertical axis, the rotor having a collar on its lower end.
2. Description of the Prior Art
In the past, plant material lying on the ground was tedded by haying machines of various types or laid down in windrows. Windrows were collected by pick-up machines and compressed by presses into bales, or conveyed to a truck, or processed in a chopper. All the prior devices, whether driven by a power take-off or traction driven, have one thing in common: they are fitted with spring steel prongs that probe the ground and transport the plant material.
All the prior devices have an important drawback: the spring steel prongs that work and transport the plant material have only a limited life. This is due to the strains to which the prongs are subjected by the unevenness of the ground and the plant material to be transported. These elements may break unnoticed during operation and a part of the element, usually composed of spring steel, gets into the harvested crop where it is practically undetectable. The next processing machine, whether it is a press or a chopper or the like, suffers severe damage from these hardened metal parts and requires expensive repairs.
This serious problem has been recognized and recently devices of the kind described above that operate without prongs, have been marketed.
FIG. 1 shows a device illustrating the state of the art. The apparatus attached to a 3-point hitch of a tractor comprises essentially a crossbeam with a divided drive shaft, driven by a power take-off, which causes three drum-shaped rotors to rotate. On the bottom of the rotors there are collars made of flexible material that probe the ground, pick up the plant material and, in interaction with conveyor elements, move it back to the side so that a windrow is formed.
However, this device when utilized as a haying machine has the great disadvantage that the conical collar is expensive and is quickly worn down due to constant contact with the ground and plant material. This wear, which is especially noticeable on the periphery of the flexible collar, also affects the quality of the work of the device and especially its ability to pick up and transport plant material. The user should not be expected to have to keep replacing this expensive part as a unit.